Devices, systems and methods useable for treating frontal sinusitis

ABSTRACT

Devices, systems and methods wherein a dilator, such as a balloon or other expandable member, is positionable within the frontal sinus ostium and adjacent frontal recess and useable to dilate the frontal sinus ostium and substantially all of the frontal sinus recess without requiring repositioning and repeated re-expansion of the dilator. One balloon catheter device of the invention comprises a catheter body that is less than about 50 cm in length (and in some embodiments less than 25 cm in length and a semi-compliant or non-compliant balloon on the catheter body. The balloon may have a working length of about 12 mm to about 30 mm and a width at its widest point when fully inflated of about 2 mm to about 7 mm. Such balloon may be constructed to withstand inflation pressures of about 12 atmospheres. In some embodiments, the dilator is advanced through or over a guide (e.g., guidewire or guide catheter) that has a preformed shape.

RELATED APPLICATIONS

This application is a continuation-in-part of copending U.S. patentapplication Ser. No. 11/150,874 entitled “Devices, Systems and MethodsUseable for Treating Sinusitus” filed on Jun. 10, 2005, which is acontinuation in part of U.S. patent application Ser. No. 10/944,270entitled “Apparatus and Methods for Dilating and Modifying Ostia ofParanasal Sinuses and Other Intranasal or Paranasal Structures” filed onSep. 17, 2004, which is a continuation-in-part of Ser. No. 10/829,917entitled “Devices, Systems and Methods for Diagnosing and TreatingSinusitis and Other Disorders of the Ears, Nose and/or Throat” filed onApr. 21, 2004, the entire disclosures of such earlier filed applicationsbeing expressly incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to medical devices and methodsand more particularly to minimally invasive, devices, systems andmethods for treating sinusitis and other ear, nose & throat disorders.

BACKGROUND

In human beings, the frontal paranasal sinuses reside on either side ofthe forehead adjacent to and above the orbits. The right and leftfrontal sinuses are divided by an intersinus septum. Each frontal sinushas a natural opening (i.e., an ostium) formed in the posteromedialaspect of the sinus floor. In most patients, a narrow anatomicalpre-chamber known as the frontal recess extends between the frontalsinus ostium and the nasal cavity. The frontal recess is a bonystructure covered by mucosal tissue. The anterior border of the frontalrecess is formed by the posterior wall of the agger nasi cell and themedial aspect of the frontal recess relates to the lateral lamella ofthe cribriform and the cribriform plate. Mucous normally drains out ofthe frontal sinus ostium, through the frontal recess, and into the nasalcavity. The ostium and frontal recess are sometimes referred to incombination as the frontal outflow tract (FOT). In many individuals, theFOT is a relatively long passage.

In patients suffering from acute frontal sinusitis, the FOT may becomeinflamed and occluded, thereby impeding natural drainage from thefrontal sinus cavity and allowing infectious organisms to thrive withinthe frontal sinus cavity and associated ethmoid air cells. Acute frontalsinusitis is sometimes associated with intracranial and/or ocularcomplications. Ocular complications that are known to result fromfrontal sinusitis include thrombosis, thrombophlebitis, cellulites andorbital abscesses. One type of orbital abscess, known as a Pott puffytumor, is associated with considerable soft tissue swelling over thefrontal bone. Intracranial complications associated with frontalsinusitis include meningitis, brain abscess, epidural empyema, subduralempyema, and cerebral empyema.

In current practice, surgical procedures are performed for the treatmentof acute frontal sinusitis only after the condition has failed torespond to conservative therapy (e.g., administration of antibiotics andmucolytic agents along with topical steroids and topical or systemicdecongestants) or when other complications are present or when theinfection has recurred more than 3-4 times in a year. The surgicalprocedures used to treat acute frontal sinusitis include functionalendoscopic sinus surgery (FESS) procedures as well a open surgicalprocedures.

In FESS procedures, a nasal endoscope and other instruments (e.g.,seekers, probes, rongeurs, a drills, and bony curettes) are insertedtransnasally and used to improve patency of the FOT or otherwise improvedrainage from the diseased frontal sinus. This process often involvesthe performace of an uncinectomy, anterior ethmoidectomy, agger nasiremoval, and/or resection of the anterosuperior attachment of the middleturbinate. In some cases, the superior aspect of the nasal septum may beremoved in a bilateral frontal sinus drill-out procedure. In manyfrontal sinus FESS procedures, disease of the anterior ethmoids is alsobe addressed during the surgery. In some cases, a stent is placed withinthe surgically altered FOT to maintain its patency in the weeksfollowing the surgery. In cases where a stent is implanted, the patientis typically advised to irrigate the stent several times a day for up to5-7 weeks after the surgery.

Postoperatively, it is typically necessary for FESS patients to visitthe surgeon periodically for postoperative care, such as debridement,removal of clots, removal of granulation tissue, removal of crust,removal of polyps, etc.

FESS treatment of frontal sinusitis does have some disadvantages. Forexample, the FESS procedures are technically complex, accessing diseasein the supraorbital frontal sinus cell is difficult, postoperative carecan be laborious, confirming the patency of the surgically altered FOTmay be difficult during the initial postoperative period.

Moreover, given the risks associated with the FESS procedure, somepatients with relatively mild frontal sinusitis are not considered to becandidates for the procedure even though the available medical therapiesmay provide them with less than complete relief.

In the trephination procedure, a small supraorbital incision is madebelow the medial eyebrow and the underlying periosteum is elevated. Abore hole is then made through the skull bone and into the sinus cavity.The interior or the sinus may then be cleaned and small tubes may beinserted and used for future irrigation or drainage. In some cases,trephination may be performed concurrently with endoscopic frontal sinussurgery. In some patients, the intersinus septum may be removed and asingle opening may be created through which both frontal sinuses maydrain into the nasal cavity. The main contraindication to thetrephination procedure is the presence of an aplastic frontal sinus.

Other open surgeries, known generally as frontoethmoidectomies, havealso been used to treat frontal sinusitis and associated ethmoiddisease. These procedures have been performed by various approaches,including those known as the Lynch approach, the Killian method, theReidel method and the Lothrop or Chaput-Meyer approach.

Another group of open procedures used to treat frontal sinusitis areknown generally as osteoplastic flap procedures. These osteoplastic flapprocedures are typically employed only in severe cases where frontalsinusitis is refractory or accompanied by intracranial complications.Osteoplastic flap procedures have been performed by various approaches,including a coronal approach, a midline forehead approach and a browincision approach. After an initial incision is made by one of thesethree approaches, a template may be used to outline the frontal sinus.An incision is then made through the periosteum at a location slightlyabove the outline of the sinus. The periostium is elevated and a saw isused to cut into the frontal sinus. Small cuts may also be made abovethe glabella to loosen the frontonasal suture. In this manner, anosteomeatal flap is created, exposing the interior of the frontal sinus.The surgeon may then remove the diseased sinus mucosa and may also alterthe structure of the sinus and/or FOT, such as by removal of theintersinus septum. The remaining frontal sinus cavity is then packedwith autogenous fat or other materials (Gelfoam, Teflon, fat, paraffin,silastic sponge, and cartilage), the osteomeatal flap is replaced andthe periostium and skin layers are then closed with sutures. Somemodified versions of the osteoplastic flap procedure also include theuse of a pericranial flaps and/or cancellous bone grafts.

In general, open surgical procedures do provide excellent visualizationof the interior of the sinus, thereby enabling the surgeon to see andcorrect a variety of problems. However, these open procedures can beextremely invasive. They also result in at least some visible scarringand typically involve substantial obliteration of existing anatomy tocreate an open frontonasal communication.

The prior art has included some disclosure of the use of ballooncatheters to dilate anatomical passages and improve drainage fromparanasal sinuses. For example, U.S. Pat. No. 2,525,183 (Robison)discloses an inflatable pressure device which can be inserted followingsinus surgery and inflated within the sinus. Also, United States PatentPublication No. 2004/0064150 A1 (Becker) discloses balloon catheterswherein a balloon is mounted on a stiff hypotube that may purportedly bepushed into a sinus. The stiff hypotube has a fixed pre-set curve orangle. Additionally, an abstract entitled Balloon Dilatation ofRecurrent Ostial Occlusion of the Frontal Sinus, by D. Göttmann, M.Strohm, E.-P. Strecker and D. E. Karlsruhe describes balloon dilatationof recurrent ostial occlusion of the frontal sinus in seven patientssuffering from recurring chronic frontal sinusitis who had undergonebetween two and four prior surgeries for the condition. Using endonasalaccess the ostium of the frontal sinus was crossed with an angiographiccatheter and a hydrophilic guidewire under fluoroscopic control. Then,the stenosed ostium was dilated with a high pressure percutaneoustransluminal angioplasty balloon having a deflated diameter of 5 mm andan inflated diameter of 8 mm. This procedure was performed 2 to 8 timesin each patient, at intervals of 2 to 12 weeks. The abstract reportsthat all of these procedures were technically successful and there wereno complications. Although the prior art does disclose some uses ofballoons to dilate the ostia of paranasal sinuses, the prior art has notdisclosed specifically sized or configured balloons or other dilatorsthat may be used to dilate the entire length of a FOT (i.e., the frontalsinus ostium as well as an adjacent frontal recess) in a single step orwithout the need for repositioning and multiple inflations of theballoon.

Because the surgical treatments for frontal sinusitis are invasive andassociated with various risks and complications, there remains a needfor the development of new devices and techniques for treatment offrontal sinusitis with less trauma and less risk of complications. Also,since surgical treatments for frontal sinusitis are typically reservedfor only severe or refractory cases, there remains a need for thedevelopment of new interventions that go beyond the previously availableconservative treatments (e.g., medical therapy with antibiotics,steroids, mucolytics, saline lavage, etc.) but do not involve the tissuetrauma.

SUMMARY OF THE INVENTION

The present invention provides improved dilator systems and methodswherein a dilator of suitable length is used to simultaneously dilatethe frontal sinus ostia and frontal recesses, and optionally to dilatethe ostia of other sinuses as well.

In accordance with an embodiment of the invention, there is provided amethod for improving outflow through the frontal sinus ostium andadjacent frontal recess in a human or animal subject. This methodgenerally comprises the steps of (A) providing a dilator that has acollapsed configuration and an expanded configuration, said dilatorbeing of a length that is approximately as long as or longer than thelength of the frontal sinus ostium and frontal recess combined; (B)positioning the dilator such that it occupies the frontal sinus ostiumand at least substantially all of the frontal recess while in itscollapsed configuration; and (C) causing the dilator to expand to itsexpanded configuration, thereby dilating the frontal sinus ostium and atleast substantially all of the frontal recess. In some embodiments, thedilator may be mounted on a catheter and the catheter may be insertedtransnasally and advanced to a location where the dilator is positionedwith the frontal sinus ostium and substantially all of the adjacentfrontal recess. The dilator may comprise a balloon or any otherexpandable structure (e.g., an expandable systems of wires, mesh, etc.).In embodiments where the dilator is a balloon, the balloon may beelongated and non-compliant or semi-compliant and, optionally, may be atleast partially coated with a protective coating. Examples of materialsof which the balloon may be formed include polyethylene terephthalate(PET), Nylon and those materials referred to in U.S. Pat. No. 5,264,260(Saab) which is expressly incorporated herein by reference. Examples ofprotective coatings that may be used include but are not necessarilylimited to those described in U.S. Pat. No. 5,599,576 (Opolski) and/orU.S. Pat. No. 5,766,158 (Opolski), both of which are expresslyincorporated herein by reference. In some embodiments, the protectivecoating may comprise a matrix polymer and a reinforcing agent. In someembodiments, a primer layer may optionally be disposed between theballoon surface and the protective coating. The matrix polymer of theprotective coating may, for example, comprise a urethane, acrylic orepoxy. The reinforcing agent may, for example, be lamellar, platelet, orfiber-like in structure and may have a higher surface hardness than thesurface hardness of the material of which the balloon is formed. Suchreinforcing agent may, for example, comprise a micaceous pigment, glassfiber, lamellar platelet, flake pigment, tungsten powder and/or fibers.In some embodiments, the protective coating may have a thickness in therange of about 0.1 mil to about 3 mil and in some embodiments suchcoating thickness may be in the range of about 0.5 mil to about 2 mil.In some embodiments, the protective coating may further include acrosslinking agent (e.g., aziridine, carbodiimide, urea formaldehyde,melamine formaldehyde condensate, epoxy, isocyanate, titanate,zircoaluminate, zinc crosslinker, silane, etc.). In some embodiments,the protective coating may further include an additive selected from thegroup consisting of radio pacifiers, anti-slip additives, anti-maradditives, and antimicrobial agents, and therapeutic agents or othertherapeutic or diagnostic substances.

Further in accordance with the invention, there is provided a systemthat is useable to perform the above summarized method. Such systemgenerally comprises a dilation catheter having a dilator as summarizedhereabove and a guide (e.g., a tubular guide through which the dilationcatheter is advanced or an elongate guide member such as a guidewireover which the dilation guide catheter is advanced). The guide isuseable to guide the positioning of the dilator. In at least someembodiments, the guide may be of substantially fixed shape (e.g.,manufactured to a predetermined shape or at least partially malleable sothat the surgeon may bend it to a desired substantially fixed shapeprior to insertion). In at least some embodiments where the guide has asubstantially fixed shape, such shape will include a curve near thedistal end of the guide to facilitate positioning of the distal end ofthe guide within or adjacent to the frontal recess. The guide isinsertable through one of the subject's nostrils and advanceable to aposition where the distal end of the guide is adjacent to or within thefrontal recess. Thereafter, the dilation catheter is advanceable over orthrough the guide to a position where the dilator is positioned withinthe frontal sinus ostium and frontal recess (or other ostium orstructure to be dilated). Thereafter, the dilator may be expanded tocause dilation of the frontal sinus ostium and substantially all of theadjacent frontal recess (or whatever other ostium or anatomicalstructure is to be dilated. In at least some embodiments, the dilationcatheter may have a length of or less than 50 cm. In at least someembodiments, the dilation catheter may have a length of or less than 42cm. In at least some embodiments, the dilation catheter may have alength of or less than 25 cm. Also, in at least some embodiments, thedilator may be less than 1 mm wide at its widest point while in itscollapsed configuration and more than 3 mm wide at its widest point whenin its expanded configuration. Also, the dilator itself may have a havea length of more than 10 mm (e.g., a 24 mm dilator may be used to dilatethe frontal sinus ostium and substantially all of the adjacent frontalrecess in most adult or fully grown humans. The dilator may comprise aballoon or any other expandable structure (e.g., an expandable systemsof wires, mesh, etc.). In embodiments where the dialtor comprises aballoon the balloon may be constructed and/or coated as described in thepreceding paragraph hereabove and in the United States patentsincorporated by reference therein.

Further aspects, details and embodiments of the present invention willbe understood by those of skill in the art upon reading the followingdetailed description of the invention and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of the paranasal anatomy of a human head wherein adilation catheter system of the present invention has been inserted andis being used to simultaneously dilate the frontal sinus ostium andadjacent frontal recess.

FIG. 2 is a sagital sectional view through the right nasal cavitywherein a dilation catheter system of the present invention has beeninserted and is being used to simultaneously dilate the frontal sinusostium and adjacent frontal recess.

FIGS. 3A-3C are side views of devices that comprise one embodiment of adilation catheter system of the present invention. FIG. 3A shows aguidewire, FIG. 3B shows a dilation catheter and FIG. 3C shows a tubularguide.

FIG. 4 is a broken, side elevational view of a rapid exchange embodimentof a dilation catheter device of the present invention.

FIG. 5 is a partial perspective view of an embodiment of a dilationcatheter device of the present invention having a tapered dilationballoon.

FIG. 6A is a partial perspective view of an embodiment of a dilationcatheter device of the present invention having a dilation balloon thatincorporates a force concentrating member.

FIG. 6B is a cross sectional view through line 6B-6B of FIG. 6A.

DETAILED DESCRIPTION

The following detailed description, the accompanying drawings and theabove-set-forth Brief Description of the Drawings are intended todescribe some, but not necessarily all, examples or embodiments of theinvention. The contents of this detailed description do not limit thescope of the invention in any way.

A number of the drawings in this patent application show anatomicalstructures of the ear, nose and throat. In general, these anatomicalstructures are labeled with the following reference letters:

-   -   Nasal Cavity NC    -   Nasopharynx NP    -   Frontal Sinus FS    -   Frontal Sinus Ostium FSO    -   Frontal Recess FR    -   Ethmoid Air Cells EAC    -   Intersinus Septum ISS    -   Sphenoid Sinus SS    -   Sphenoid Sinus Ostium SSO    -   Maxillary Sinus MS

The term “diagnostic or therapeutic substance” as used herein is to bebroadly construed to include any feasible drugs, prodrugs, proteins,gene therapy preparations, cells, diagnostic agents, contrast or imagingagents, biologicals, etc. Such substances may be in bound or free form,liquid or solid, colloid or other suspension, solution or may be in theform of a gas or other fluid or nan-fluid. For example, in someapplications where it is desired to treat or prevent a microbialinfection, the substance delivered may comprise pharmaceuticallyacceptable salt or dosage form of an antimicrobial agent (e.g.,antibiotic, antiviral, antiparasitic, antifungal, etc.), acorticosteroid or other anti-inflammatory (e.g., an NSAID), adecongestant (e.g., vasoconstrictor), a mucous thinning agent (e.g., anexpectorant or mucolytic), an agent that prevents of modifies anallergic response (e.g., an antihistamine, cytokine inhibitor,leucotriene inhibitor, IgE inhibitor, immunomodulator), etc. Othernon-limiting examples of diagnostic or therapeutic substances that maybe useable in this invention are described in copending U.S. patentapplication Ser. No. 10/912,578 entitled Implantable Devices and Methodsfor Delivering Drugs and Other Substances to Treat Sinusitis and OtherDisorders filed on Aug. 4, 2004, the entire disclosure of which isexpressly incorporated herein by reference.

The term “frontal recess” means the natural or surgically alteredopening or passageway extending from an ostium or opening in a frontalsinus into the nasal cavity.

The term “frontal outflow tract” or the acronym “FOT” means an ostium oropening in a frontal sinus along with any frontal recess that extendsfrom that ostium or opening to the nasal cavity.

Each of the terms “ostium,” “opening of a paranasal sinus” or “openingin a paranasal sinus” as used herein shall mean any accessible openingin a paranasal sinus or cranio-facial air cell, including but notlimited to; natural ostia, surgically or medically altered ostia,surgically created or man made openings, antrostomy openings, ostiotomyopenings, trephination openings, burr holes, drilled holes,ethmoidectomy openings, anatomical passageways, natural or man madepassages, etc., unless otherwise specified.

The term “working length” as used herein with respect to balloons orother dilators shall mean the length of that portion of the balloon orother dilator that actually contacts and dilates tissue. For example, inthe case of a balloon that, when inflated, has a cylindrical midregionthat contacts and dilates adjacent tissue and tapered end regions thatdo not contact and dilate adjacent tissue, the working length of suchballoon is the length of the cylindrical midregion that contacts anddilates adjacent tissue.

Optionally, any of the working devices and guide catheters describedherein may be configured or equipped to receive or be advanced over aguidewire or other guide member (e.g., an elongate probe, strand ofsuture material, other elongate member) unless to do so would render thedevice inoperable for its intended purpose. Some of the specificexamples described herein include guidewires, but it is to beappreciated that the use of guidewires and the incorporation ofguidewire lumens is not limited to only the specific examples in whichguidewires or guidewire lumens are shown. The guidewires used in thisinvention may be constructed and coated as is common in the art ofcardiology, but may be substantially shorter than those used incardiology applications. This may include the use of coils, tapered ornon-tapered core wires, radiopaque tips and/or entire lengths, shapingribbons, variations of stiffness, PTFE, silicone, hydrophilic coatings,polymer coatings, etc. For the scope of this invention, these wires maypossess dimensions of length between 5 and 120 cm and outer diameterbetween 0.05″ and 0.50″. In embodiments of the invention where anelongate guide member (e.g., a guidewire) of a substantially fixed shapeis specified, such may be accomplished by utilizing a guide member(e.g., guidewire) that is fully or partially formed of rigid ormalleable material and is pre-shaped to a desired substantially fixedconfiguration (e.g., a desired curve near its distal end) prior toinsertion into the subject's body.

It is to be appreciated that various modalities can be used with thedevices and methods disclosed herein for navigation and imaging of thedevices within the anatomy. For example, the devices disclosed hereinmay comprise an endoscope for visualization of the target anatomy. Thedevices may also comprise ultrasound imaging modalities to image theanatomical passageways and other anatomical structures. The devicesdisclosed herein may comprise one or more magnetic elements especiallyon the distal end of the devices. Such magnetic elements may be used tonavigate through the anatomy by using external magnetic fields. Suchnavigation may be controlled digitally using a computer interface. Thedevices disclosed herein may also comprise one or more markers (e.g.infra-red markers). The markers can be used to track the preciseposition and orientation of the devices using image guidance techniques.Several other imaging or navigating modalities including but not limitedto fluoroscopic, radiofrequency localization, electromagnetic, magneticand other radiative energy based modalities may also be used with themethods and devices disclosed herein. These imaging and navigationtechnologies may also be referenced by computer directly or indirectlyto pre-existing or simultaneously created 3-D or 2-D data sets whichhelp the doctor place the devices within the appropriate region of theanatomy. Examples of specific navigation apparatus and methods that maybe used in conjunction with the devices and methods of this inventioninclude but are not limited to those described in co-pending U.S. patentapplication Ser. No. 11/037,548 entitled “Devices, Systems and MethodsFor Treating Disorders of the Ear, Nose and Throat,” which is expresslyincorporated herein by reference.

Also, as described more fully hereblow, the devices of the presentinvention may include visible markers that may be viewed directly orendoscopically to facilitate the desired positioning of the deviceswithin the body.

FIGS. 1-2 show the use of an embodiment of a dilation catheter system 10to simultaneously dilate a frontal sinus ostium FSO and adjacent frontalrecess FR in a human subject. Frontal recess anatomy has heretofore beengenerally taught as having an hour glass shape so it was believed that arelatively short dilator (such as a balloon) was all that was needed todilate most frontal sinus anatomy. Unexpectedly, however, Applicantshave discovered that in a fairly large population of patients there areactually multiple constrictions along the frontal recess. As a result,Applicants developed the present invention. In general, the embodimentof the dilation catheter system 10 shown in the drawings comprises adilation catheter 12, a tubular guide 14 and a guidewire 16. Thesecomponents of the system 10 are shown in greater detail in FIGS. 4A-4C.

Generally, at least one of the tubular guide 14 and/or the guidewire 16will have a predetermined (e.g., substantially fixed) shape (e.g.,having a fixed curve near its distal end) prior to its insertion intothe body. This fixed shape facilitates easy insertion of the guidewire16 and/or tubular guide 14 into the frontal recess or other desiredlocation within the nasal cavity or paranasal sinus anatomy. In someinstances, one or both of the guidewire 16 and/or tubular guide 14 willbe of generally rigid construction and manufactured in the desiredpredetermined or substantially fixed shape. In other instances, all or aportion of the guidewire 16 and/or tubular guide 14 may be of malleableconstruction such that the surgeon may bend or pre-form that guidewire16 or tubular guide 14 to the desired shape prior to its insertion intothe subject's body.

In the particular example shown in the drawings and discussed herebelow,the tubular guide 14 is generally rigid and has a substantially fixedshape. The guidewire 16 is substantially flexible and use of theguidewire is optional. It is to be appreciated, however, that in otherembodiments the guidewire 16 may be more rigid and of substantiallyfixed shape and use of the tubular guide 16 may be optional.

In this example, the guidewire 16, seen in FIG. 3A, is a flexible sinusguidewire with a soft tip, a length of 100 cm and a diameter of 0.035inch. This guidewire is commercially available under the name Relieva™Sinus Guidewire from Acclarent, Inc., Menlo Park, Calif. It will beappreciated, however, that other guidewires and other sizes ofguidewires may alternatively be used.

Also, in this example, the tubular guide 14 as seen in FIG. 3B,comprises a semi-flexible tube with a malleable proximal shaft 30 and aplastic distal portion 32 having a curve 34 formed near its distal endDE. A radiopaque marker 38 is mounted near the distal end DE of thistubular guide 14. This tubular guide is available commercially under thename Relieva™ Sinus Guide Catheter from Acclarent, Inc. of Menlo Park,Calif. This tubular guide 14 is available with a range of curves 32(i.e., 0°, 30°, 70°, 90° and 110°). Typically, for frontal sinusprocedures such as that described herein a curve of 70° is mostsuitable. It will be appreciated, however, that other guidewires andother sizes of guidewires may alternatively be used.

The dilation catheter 12 of this example, as seen in detail in FIG. 3C,comprises an elongate catheter body 18 having a proximal end PE and adistal end DE. An elongate balloon 20 is mounted on the catheter body 18at a location near its distal end DE. This balloon 20 has a workinglength L that is specifically sized to extend from the frontal sinusostium FSO through substantially all of the frontal recess FR, thusrendering this balloon 20 capable of dilating substantially the entirefrontal outflow tract (i.e., the frontal sinus ostium and all or nearlyall of the adjacent frontal recess), without the need for repeatedinflations of the balloon 20 with longitudinal repositioning of thecatheter between inflations. In this regard, although it may be deemedappropriate to repeat inflation of the balloon 20 more than one time todilate the frontal sinus ostium FSO and adjacent frontal recess FR, nolongitudinal repositioning of the catheter body 18 will be requiredbetween such inflations. This dilation catheter 12 is availablecommercially under the name Relieva™ Sinus Balloon Catheter fromAcclarent, Inc., Menlo Park, Calif. A fixed guidewire 28 may optionallyextend from the distal end of the dilation catheter 12, as seen in FIG.3C. Such fixed guidewire 28 may allow the dilation catheter 12 to beused without a separate guidewire 16.

The actual working length L and diameter of the balloon 20 may varydepending on the anatomy, age and/or size of the subject. The workinglength of the balloon can be between about 12 mm and 30 mm. For example,the following table sets forth a non-limiting example different balloonsizes that may be provided for treatment of frontal sinusitis insubjects of normal body size and weight ranging in age from childhood toadulthood.

Typical Patient Age Dilator (e.g., Balloon) Width Dilator (e.g., Range(Fully Expanded) Balloon) Working Length >17 about 5 mm to about 7 mmabout 24 mm 14-17 About 4 mm to about 7 mm About 21 mm 10-14 About 3 mmto about 6 mm About 18 mm  6-10 About 2 mm to about 5 mm About 15 mm <6About 2 mm to about 4 mm About 12 mm

Applicant's current data suggests that a balloon 20 having a workinglength of about 24 mm and a fully expanded width of about 5 mm to about7 mm may be used to expand the frontal sinus ostium FSO as well assubstantially all of the adjacent frontal recess FR in most adult orfully grown humans without the need for repeated inflations of theballoon 20 or without longitudinal repositioning of the catheter betweeninflations.

The procedure by which the devices are inserted and used may varysomewhat from surgeon to surgeon and/or from case to case. Oneparticular, non-limiting example of such a procedure is describedherebelow with reference to the showings of FIGS. 1 and 2.

During performance of this procedure, an endoscope, such as a Karl StorzHopkins II 4 mm scope with a 70 degree viewing angle may optionally beinserted into the nose and used, alone or in combination with otherimaging techniques, to view the advancement and positioning of devicesduring the procedure in accordance with known practice or as describedin U.S. patent application Ser. Nos. 10/829,917; 10/944,270; 11/037,548;11/193,020; 11/150,847; 11/116,118, each of which is expresslyincorporated herein by reference. Alternatively or additionally,radiographic imaging (e.g., C-arm fluoroscopy) may be used to view thepositioning and guide the placement of devices during the procedure inaccordance with known practice or as described in U.S. patentapplication Ser. Nos. 10/829,917; 10/944,270; 11/037,548; 11/193,020;11/150,847; 11/116,118, each of which is expressly incorporated hereinby reference. Also, alternatively or additionally, the devices used inthis procedure may be equipped with sensors and image guidancetechnology may be used to view the positioning and guide the placementof devices during the procedure in accordance with known practice or asdescribed in U.S. patent application Ser. No. 11/116,118, which isexpressly incorporated herein by reference.

In this example, the guidewire 16 may be initially introduced, distalend first, into the lumen of the tubular guide 14. Thereafter, thetubular guide 14 (with the guidewire 16 inserted therein) is insertedthrough the subject's nostril with the curve 32 of the tubular guide 14pointing upwardly. The distal end DE of the tubular guide 14 ismaneuvered through the middle meatus to a position where its distal endDE is adjacent to and in alignment with the frontal recess FR. Theguidewire 16 is then advanced out of the open distal end DE of thetubular guide 14, through the frontal recess FR, through the frontalsinus ostium FSO and into the frontal sinus FS. In some cases, it may bedesirable to push a length of the guidewire into the frontal sinus FSsuch that it becomes coiled within the sinus cavity as seen in FIGS. 1and 2. This tends to deter inadvertent slippage of the guidewire 16 outof position and the coiled guidewire 16 within the frontal sinus FS maybe viewed by radiographic means to verify that the FOT has beensuccessfully wired.

It is to be appreciated that, although the dilation catheter 12 shown inFIGS. 1-2 and 3C is an over-the-wire type device that has a guidewirelumen that extends from one end of the catheter to the other, variousother guidewire lumen configurations and/or fixed guidewire tips may beemployed instead. For example, a guidewire may be affixed to and extenddistally from the distal end of the catheter body 18. Or, as shown inthe alternative example of FIG. 4, a rapid exchange embodiment of thedilation catheter 12 a may be utilized. This rapid exchange embodimentof the dilation catheter 12 a comprises a catheter body 18 a having aproximal hub 22 a on its proximal end and a guidwire lumen that extendsfrom a side port 42 located between the proximal and distal ends of thecatheter body 18 a though an opening in the distal end of the catheterbody 18 a. In this manner, the guidewire 28 will extend through only adistal portion of the catheter body 18 a and the proximal portion of theguidewire will be outside of the catheter body 18 a as shown.

It is to be further appreciated that, in at least some embodiments,substances (e.g., therapeutic or diagnostic substances, radiographiccontrast medium, medicaments, lavage fluid, etc.) may be injectedthrough a lumen of the catheter body 18. In some embodiments, theguidewire 28 may be smaller in diameter than the guidewire lumen suchthat substances may be injected through the guidewire lumen even whilethe guidewire is positioned therein.

Thereafter, the proximal end PE of the guidewire 16 is inserted into thedistal opening of a guidewire lumen that extends through the dilationcatheter 12 and the dilation catheter 12 is advanced over the guidewire16 and through the lumen of the tubular guide 14 to a position where theballoon 20 occupies the frontal sinus ostium FSO and substantially allor all of the adjacent frontal recess FR. An inflator device (e.g., theRelieva™ Sinus Balloon Inflation Device, Aclarent, Inc., Menlo Park,Calif.) is then connected to the inflation sidearm 26 of the dilationcatheter's proximal hub 22 and is used to inflate the balloon 20 to itsexpanded configuration. Typically, in applications where the balloon 20is used to dilate the frontal sinus ostium FSO and adjacent frontalrecess FR, this balloon will be inflated to a pressure of approximately4-12 ATM. The balloon 20 may reach its nominal (target) diameter at aninflation pressure of approximately 4-8 ATM. This inflation may berepeated one or more times at the discretion of the surgeon, but norepositioning of the balloon 20 is required between successiveinflations. In this manner, the frontal sinus ostium FSO and frontalrecess FR are dilated, thereby improving patency of the FOT andfacilitating drainage from and healing of the diseased frontal sinus FS.

If the working length L of the balloon 20 is longer than the length ofthe frontal sinus ostium FSO and adjacent frontal recess FR, a proximalportion of the balloon may be permitted to remain within the distal endof the tubular guide 14 or another suitable sheath or constrainingstructure such that only a portion of the balloon 20 becomes inflated.This essentially provides a balloon 20 of adjustable length.Alternatively or additionally, the diameter of the balloon 20 may alsovary over its length. For example, a 24 mm long balloon 20 may have afirst region (e.g., 16 mm) which inflates to a first diameter (e.g., 7mm) and a second region that inflates to a second diameter (e.g., 5 mm).In another example, shown in FIG. 5, a dilation catheter 12 b maycomprise a catheter body 18 b having a balloon 20 b mounted thereon,such balloon 20 b being may be continuously tapered such that one end ofthe balloon 20 b inflates to a first diameter and the other end of theballoon 20 b inflates to a smaller second diameter, with a continuousdiametric taper therebetween.

Also, alternatively or additionally, as shown in FIGS. 6A and 6B, anembodiment the dilation catheter 12 c may comprise a catheter body 18 chaving a balloon 20 c mounted thereon, wherein such balloon 20 cincorporates one or more force concentrating members 44 (such aslongitudinal wires embedded in the wall of the balloon 20 c) or othersurface protrusion(s) that concentrate the dilatory force of the balloonin specific area(s) rather than allowing the balloon 20 c to exert thesame outwardly directed dilatory force about its entire diameter.

Various other balloon shapes and balloon constructions may beincorporated in the dilation catheters 12, 12 a, 12 b or 12 c includingthose described in the parent patent applications of which thisapplication is a continuation-in-part. Some particular non-limitingexamples of such shapes and/or constructions include the following:

-   -   The balloon or other dilator may additionally be constructed to        deliver diagnostic or therapeutic substances to adjacent        tissues, such as through pores, coatings, micro-penetrating        members, etc.    -   The balloon material may be of varying thickness along the        length of the balloon to enhance folding or to permit it to        expand in an intentionally non-uniform fashion.    -   To prevent “winging” the balloon may be preshaped with set        ‘hinge’ areas that naturally fold when the balloon is        deflated—these hinge areas may run longitudinally along the        balloon or may be helically located.    -   The catheter shaft extending through the balloon may be        longitudinally moved by the operator to lengthen or shorten the        balloon length to adjust to different anatomies.    -   The distal tip of the balloon may be curved to facilitate        placement and also to orient the tip away from the skull base.

As seen in FIG. 2, The medial wall of the orbit (specifically the laminapapyracea) is reinforced by ethmoid air cells that form a “honeycomb”structure between the medial wall of the orbit and the frontal recessFR. In at least some applications of the present invention, dilation ofthe frontal recess FR causes bone to become cracked, fractured,rearranged or repositioned and, in at least some cases, results incompression or remodeling of one or more ethmoid air cells EAC.

It is to be appreciated that the invention has been described hereabovewith reference to certain examples or embodiments of the invention butthat various additions, deletions, alterations and modifications may bemade to those examples and embodiments without departing from theintended spirit and scope of the invention. For example, any element orattribute of one embodiment or example may be incorporated into or usedwith another embodiment or example, unless to do so would render theembodiment or example unsuitable for its intended use. Also, where thesteps of a method or process are described, listed or claimed in aparticular order, such steps may be performed in any other order unlessto do so would render the embodiment or example not novel, obvious to aperson of ordinary skill in the relevant art or unsuitable for itsintended use. All reasonable additions, deletions, modifications andalterations are to be considered equivalents of the described examplesand embodiments and are to be included within the scope of the followingclaims.

1.-84. (canceled)
 85. A method for dilating a frontal recess in a humanor animal subject with a dilation catheter, the dilation cathetercomprising a catheter shaft, a dilator positioned along a distal portionof the catheter shaft and having a sufficient length to extend throughthe frontal recess, the method comprising: (a) inserting a guide into ahead of the subject; (b) advancing the guide to the frontal recess, thenstopping advancement of the guide when a distal portion of the guide ispositioned within or adjacent to the frontal recess; (c) advancing thedilation catheter relative to the guide to position the dilator withinthe frontal recess; and (d) expanding the dilator, wherein expansion ofthe dilator results in dilation of the frontal recess.
 86. The methodaccording to claim 85, wherein the dilation catheter further comprises aguidewire lumen extending from an open proximal end of the cathetershaft to an open distal end of the catheter shaft, and the methodfurther comprises: (a) inserting a guidewire into the head of thesubject; and (b) advancing the dilator over the guidewire via theguidewire lumen of the dilation catheter.
 87. The method according toclaim 85, wherein the dilation of the frontal recess results in at leastsome breakage or movement of bone adjacent to the frontal recess. 88.The method according to claim 85, wherein the step of expanding thedilator is performed without removal, cutting, or ablation of tissue.89. The method according to claim 85, further comprising the step ofremoving, cutting, or ablating tissue within the head of the subject.90. The method according to claim 85, wherein inserting the guide intothe head of the patient further comprises inserting the guide into anostril of the patient.
 91. The method according to claim 85, furthercomprising the step of retracting the guide relative to the dilationcatheter prior to expansion of the dilator.
 92. The method according toclaim 85, further comprising the step of inserting an endoscope into thehead of the patient.
 93. The method according to claim 85, furthercomprising the step of placing a therapeutic or diagnostic substancedelivering implant within the frontal recess or frontal sinus.
 94. Themethod according to claim 85, further comprising bending at least thedistal portion of the guide to a curved shape prior to insertion in thepatient's head, wherein the curved shape is substantially retainedduring use.
 95. The method according to claim 94, wherein the step ofbending occurs at the time of manufacture, wherein the guide issufficiently rigid to maintain the curved shape until and during use.96. The method according to claim 85, wherein the distal portion of theguide comprises a curve, wherein at least a portion of the dilationcatheter is flexible to allow the dilation catheter to traverse thecurve while advancing the dilation catheter relative to the guide. 97.The method according to claim 85, wherein the method is performed incombination with a FESS procedure.
 98. The method according to claim 85,wherein expanding the dilator further comprises expanding the dilator toan expanded configuration, wherein a cross-sectional dimension of theexpanded configuration is between approximately 3 mm and approximately 7mm.
 99. The method according to claim 85, wherein the dilator includes alength of approximately 12 mm to approximately 24 mm.
 100. A method fordilating a frontal recess in a human or animal subject with a dilationcatheter and a guide for guiding the advancement of the dilationcatheter, the dilation catheter comprising a catheter shaft, a dilatorpositioned along a distal portion of the catheter shaft and having asufficient length to extend through the frontal recess, the guide membercomprising a proximal portion and a distal portion and a tubular shafttherebetween, the method comprising: (a) bending at least the distalportion of the guide to a curved shape having a bend angle prior toinsertion in the patient's head; (b) inserting the guide into a head ofthe subject, wherein the curved shape is substantially maintained duringthe insertion of the guide into the head of the subject; (c) advancingthe guide to the frontal recess; (d) advancing the dilation catheterrelative to the guide to position the dilator within the frontal recess,wherein the bend angle provides the dilation catheter access to thefrontal recess; and (e) expanding the dilator to dilate the frontalrecess.
 101. The method according to claim 100, wherein bending at leastthe distal portion of the guide to a curved shape further comprisesbending at least the distal portion such that a curve is formed withinapproximately 2 mm of a distal end of the guide.
 102. The methodaccording to claim 100, wherein the bending angle is betweenapproximately 30 degrees and approximately 110 degrees.
 103. The methodaccording to claim 100, wherein the step of bending occurs at the timeof manufacture, wherein the guide is sufficiently rigid to maintain thecurved shape until and during use.
 104. A method for dilating a frontalrecess in a human or animal subject with a dilation catheter, thedilation catheter comprising a catheter shaft, a dilator positionedalong a distal portion of the catheter shaft and having a sufficientlength to extend through the frontal recess, the method comprising: (a)inserting a guide into a head of the subject; (b) advancing the guide tothe frontal recess; (c) advancing the dilation catheter relative to theguide to position the dilator within the frontal recess; (d) retractingthe guide relative to the dilation catheter; and (e) expanding thedilator, wherein expansion of the dilator results in dilation of thefrontal recess.